Conventional toy blocks, "Lego" for example, are combined together one by one, by inserting protruding round posts on the top surface of a block in a round-holed protruding wall on the bottom surface of another block. The blocks are generally made of plastics, and the walls are liable to break and wear out because of their material so that blocks combined together often cannot hold tight together or can break, obliging a player to supplementally buy some blocks more.